gnu: python: Make 'sys.version' deterministic.

* gnu/packages/patches/python-2-deterministic-build-info.patch,
  gnu/packages/patches/python-3-deterministic-build-info.patch: New
  files.
* gnu/packages/python.scm (python-2, python): Use them.
* gnu-system.am (dist_patch_DATA): Add them.

gnu-system.am

@@ -669,8 +669,10 @@ dist_patch_DATA =						\
   gnu/packages/patches/pybugz-encode-error.patch		\
   gnu/packages/patches/pybugz-stty.patch			\
   gnu/packages/patches/pyqt-configure.patch			\
+  gnu/packages/patches/python-2-deterministic-build-info.patch	\
   gnu/packages/patches/python-2.7-search-paths.patch		\
   gnu/packages/patches/python-2.7-source-date-epoch.patch	\
+  gnu/packages/patches/python-3-deterministic-build-info.patch	\
   gnu/packages/patches/python-3-search-paths.patch		\
   gnu/packages/patches/python-disable-ssl-test.patch		\
   gnu/packages/patches/python-fix-tests.patch			\

gnu/packages/patches/python-2-deterministic-build-info.patch

@@ -0,0 +1,17 @@
+Always provide the same date and time in 'Py_GetBuildInfo'.
+This is the information shown at the REPL and in 'sys.version'.
+We cannot pass it in CPPFLAGS due to whitespace in the DATE string.
+
+--- a/Modules/getbuildinfo.c
++++ b/Modules/getbuildinfo.c
+@@ -4,6 +4,10 @@
+ #include <stdio.h>
+ #endif
+ 
++/* Deterministic date and time.  */
++#define DATE "Jan  1 1970"
++#define TIME "00:00:01"
++
+ #ifndef DATE
+ #ifdef __DATE__
+ #define DATE __DATE__

gnu/packages/patches/python-3-deterministic-build-info.patch

@@ -0,0 +1,17 @@
+Always provide the same date and time in 'Py_GetBuildInfo'.
+This is the information shown at the REPL and in 'sys.version'.
+We cannot pass it in CPPFLAGS due to whitespace in the DATE string.
+
+--- Modules/getbuildinfo.c
++++ Modules/getbuildinfo.c
+@@ -4,6 +4,10 @@
+ #include <stdio.h>
+ #endif
+ 
++/* Deterministic date and time.  */
++#define DATE "Jan  1 1970"
++#define TIME "00:00:01"
++
+ #ifndef DATE
+ #ifdef __DATE__
+ #define DATE __DATE__

gnu/packages/python.scm

@@ -94,6 +94,7 @@ (define-public python-2
         "1h7zbrf9pkj29hlm18b10548ch9757f75m64l47sy75rh43p7lqw"))
       (patches (map search-patch
                     '("python-2.7-search-paths.patch"
+                      "python-2-deterministic-build-info.patch"
                       "python-2.7-source-date-epoch.patch")))))
     (build-system gnu-build-system)
     (arguments
@@ -223,6 +224,7 @@ (define-public python
                             '("python-fix-tests.patch"
                               ;; XXX Try removing this patch for python > 3.4.3
                               "python-disable-ssl-test.patch"
+                              "python-3-deterministic-build-info.patch"
                               "python-3-search-paths.patch")))
               (patch-flags '("-p0"))
               (sha256